基于全寿命周期成本理论的水工结构维修加固决策模型

鉴于补强修复和除险加固作为水工结构领域中一项重要工作和长期任务,对保障工程服役安全、发挥工程效益、延长工程服役周期等具有极其重要的意义,在保证结构安全可靠的前提下,考虑结构性能的劣化特性,从优化工程全寿命周期成本的目标出发,引入全寿命周期成本理论,研究水工结构维修加固成本计算与决策模型及其算法,并应用于某水工结构工程中,优化制定其全寿命周期内具体维修方案。研究结果表明,文中所述模型可为制定水工结构工程在全寿命周期内的维修加固策略提供一定的科学依据。     

基于整数编码粒子群算法的树状供水管网优化

以管网年费用折算值为目标函数,以管网布置形式及管径为优化参数,建立了树状供水管网的优化设计模型.利用基于整数编码的粒子群算法对这一模型进行了求解,该方法以某一管网连接状态及各管段管径作为粒子群个体,采用整数编码,通过不断地更新粒子的位置来搜索最优的管网结构及管径值,实现了对管网布置形式及管径的同时优化.优化过程中,对进化过程中产生的不可行解进行处理,提高了优化效率.实例表明,将粒子群算法应用于树状管网优化设计中可以获得更好的优化结果和效率.     

基于多目标粒子群算法的水工结构维修加固决策方法

以往工程维修的目标多考虑当前维修费用最小化或利益最大化，缺少从工程全寿命角度考虑维修的总成本。笔者旨在从水工结构工程维修加固全寿命周期成本最小、结构服役性能最优等目标出发，引入多目标粒子群算法，研究水工结构维修加固模型及其算法，并应用于实际工程，优化制定其维修加固决策方案。研究成果表明，该方法可为水工结构工程全生命周期维修加固提供一定的科学依据。     

基于遗传算法的农村供水管网优化设计

农村饮水安全工程的供水管网优化设计,对于节约工程投资、提高工程社会效益具有重要意义。为了对供水管网进行管径优化,从经济性和可靠性出发,以投资成本最低为目标函数,以水力学指标为约束条件,建立管网优化数学模型。运用遗传算法进行模型求解,针对供水管网优化模型的特点,选取自然数编码,建立合适的适应度函数,设置选择、交叉、变异等遗传算子,并选取工程实例进行优化求解,通过与传统方法的计算结果对比,验证了遗传算法用于供水管网优化的实用性。     

泵站加压式树状供水管网优化设计研究

针对传统供水管网优化设计时未考虑整个管网的首末水头约束问题,提出了以管网系统年折算费用最小为目标函数,以水泵扬程和具有标准管径的干、支管管道长度为决策变量的泵站加压式树状供水管网优化设计数学模型。在该模型中,假定水泵扬程已知,将管网优化问题转化成管网投资线性子模型问题,并采用大系统分解-动态聚合方法对该子模型进行求解。研究结果表明,该方法寻优能力强,且计算时间短,计算结果精度较高,为泵站加压式树状供水管网系统优化设计提供了一种可行而有效的新方法。     

平原地区低压管道输水灌溉管网优化设计

本文以淮安地区水稻作物低压管道灌溉设计为研究方向,重点阐述管道输水灌溉管网优化设计方法,以管网年费用最小为目标,建立管道输水灌溉管网优化设计模型,并采用界限流量法求解,推导出相邻管径的界限流量的计算公式,从而优化管径,对合理配套机泵、管道,减少工程投资、降低运行费用,持久发挥管灌工程效益具有重要意义。     

基于模拟退火遗传算法的自压树状管网优化

将遗传算法全局优化和模拟退火的良好局部搜索能力有机结合,构造出一种退火遗传算法用于自压树状管网的优化设计方法。假定管网中每一管段最多只能由两种管径的管道组成,建立了以管网造价为目标函数,以管长、标准管径为决策变量的自压树状管网优化数学模型。采用基于不可行度的退火算法处理约束条件,应用遗传算法进行优化计算。仿真实例结果表明,该模型与算法在求解自压树状管网优化问题上,具有良好的优化性能和求解效率。     

线性信赖域算法在给水管网优化设计中的应用

提出了将给水管网优化设计分解成管径优化和流量优化的方法.对于管径优化,以不同管径管长为优化变量,建立某一流量分配下的线性规划模型.利用管道造价公式和水力计算公式,建立以流量分配为优化变量的非线性规划模型.在计算过程中,采用单纯型法求解线性规划模型,用带有约束的信赖域法求解非线性规划模型,两种算法交替计算.算例表明这一方法是可行的,能得到管网的优化设计方案.     

邙山生态园灌溉管网优化设计

为了减少郑州邙山水土保持生态园灌溉管网的投资和年运行费用,在选择喷灌技术的基础上建立了灌溉管网优化设计模型,并采用粒子群算法对模型进行求解,得到了最优管径组合.结果表明:粒子群优化算法计算的管网投资为28 125元,而采用规划法计算投资为32 254元,可见粒子群优化计算管网投资小于规划法计算投资.     

城市污水输送系统优化设计方法研究

针对城市污水输送管网工程,分别考虑了污水输送有压、无压管网系统优化问题。对于有压管网工程,建立了以加压泵站和输水管道工程年费用最小为目标函数,以加压泵站工作扬程与各管段管径为决策变量,以管段首末水头损失、各管段管道经济流速与各管段管径为约束条件的非线性模型,采用加压站工作扬程离散枚举法比选,管段管径一维动态规划选优方法进行优化计算;针对无压管网工程,同样建立了以输水管道工程年费用最小为目标函数,以各管段管径为决策变量,以管段为阶段变量,以管段首末水头损失为耦合约束条件、以各管段管道经济流速、各管段纵坡与各管段管径为决策变量可行域约束条件的一维动态规划模型。以此两种模型,可以对城市污水管网工程进行有压与无压输送方案比选,并通过实例分析验证可为城市污水输送有(无)压管网工程系统优化设计提供参考。     

A Life Cycle Oriented Multi‑objective Optimal Maintenance of Water Distribution: Model and Application

Aiming at trading off several conflicting criteria in practical maintenance in a deteriorating water distribution network, a life cycle oriented multi-objective optimization model of water distribution network maintenance is developed, which is composed of seven interrelated sub-models with different functions. This model can provide decision support for preventive maintenance decision, including identifying the pipeline that needs to be maintained, judging the time point for maintenance, determining the type of maintenance technology, calculating the economic cost of maintenance, and presenting the impact under different maintenance strategies. Based on the life cycle of each pipeline, multiple effects in the water distribution can be dynamically evaluated, such as pipeline age, failure rate, hydraulic reliability health level etc. Based on special design of chromosome gene encoding, the algorithm of elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) is incorporated to achieve multi-objective optimization solution effectively. With application of a county in Zhejiang province in China, three strategies including empirical decision single-objective optimization decision and multi-objective optimization decision are evaluated and compared to the baseline systematically. Although the annual maintenance cost of strategy III is not the lowest among those three strategies, the pipeline age, failure rate, hydraulic reliability, and health level of the water distribution network under the strategy are at the best level. With multiple objectives considered simultaneously, the results of strategy III are recommended as the optimal maintenance implementation arrangements. This model can promote to find an optimal maintenance strategy, and provide a technical support for the planning, design and implementation of maintenance arrangements of water distribution network in a long-term period.

     

供水管网优化维护的理论与技术框架分析

针对供水管网失效情况下,供水管网优化维护的问题,系统地总结了供水管网优化维护的3个阶段;提出了供水管网优化维护的3个基础理论:管道失效理论、管道可维护理论以及优化决策理论;建立了面向全生命周期的供水管网优化维护的一体化技术框架,包括数据融合、状态辨识、措施集合、优化决策以及方案实施5个方面.     

供水保障工程成本估算方法与造价控制探讨

供水是人类社会最基本需求之一,供水的可持续性对社会发展至关重要。随着经济的快速发展和城市化进程的推进,供水保障面临着诸多挑战。供水保障工程的成本估算与造价控制直接关系到供水工程的可行性和可持续性,相关研究已成为该领域研究的重点。研究表明合理规划、细致预算、竞争招标、有效管理是确保工程在预算范围内完成的关键;在运营维护阶段,设备维护、节水意识推广、人员配置优化、财务管理的健全是降低运营成本、提高效益的关键要素。     

区域供水管网DMA规划方案研究

在区域供水管网规划阶段引入DMA(District Meter Area)理念,根据自然条件并结合管网布局情况,探讨管网分区原则;在给水管网建模基础上对DMA规划方案进行评估。通过模拟计算,本规划方案能满足该区域供水安全要求;通过费用分析,在规划、设计前期实施DMA技术,可有效节省建设成本。避免在现状管网中实施分区造成的不便,为提升供水管网规划及设计水平,提高供水企业管网的管理和运营水平做出有益尝试。     

MULTI-OBJECTION OPTIMIZATION MODEL BASED ON RELIABILITY FOR WATER DISTRIBUTION SYSTEMS

1.INTRoDUCTIoNTheoptimizationofwaterdistributionsystemsbasedonreliabilityhasdrawnmoreandmoreattention-Themajorissueofwaterdistributionsystemreliabilityisconcernedwiththeabilityofthesystemtosupplydemandatthenodesordemandpointswithinthesystematrequiredminimump.essures.Theconventionaldesignprocessesforwaterdistributionsys-temsaretrialandQrrorpLoCeduresthatattempttofindadesignthatrepresentsaleast-costsolution,whicheanmeet'ng'demand.Thesetrialanderrormethodsmakenoattempttoanalyzeordefineanyrel…     

基于遗传算法的给水管网多工况优化设计

目前大多数基于遗传算法的给水管网优化设计在供水安全性和经济性方面都存在不足。本文针对这些不足,对优化设计的目标函数进行了改进,加入了流速约束,提出了流量已初分配的给水管网多工况的优化设计,并采用罚函数法予以实现。最后对青岛市出口加工区管网进行了优化求解,通过优化结果的对比,验证了该设计方法的实用性及其在供水安全性和经济性方面的优点。     

Optimization Approach to Designing Water Supply Systems in Non-Coastal Areas Suffering from Water Scarcity

This article presents a novel optimization approach to designing water supply systems in non-coastal areas with water scarcity. In such areas, high water demand caused by population increases and economic development can only be satisfied with seawater supply. Furthermore, most of the non-coastal users are located at long distances and sometimes at altitudes very diverse from the coastline, meaning long pipelines and several pumping stations will be required to effectively supply water. The proposed optimization approach based on a mixed integer nonlinear programming model offers optimal designs of water supply systems from an economic and technical perspective. It determines the location and size of desalination plants and the design of the water transport network including pipelines of specified length and diameter and pumping stations that minimize capital and operational costs of the whole system. A case study in a hyper-arid region of Chile was used to validate the applicability of the proposed model and the results show its aptitude for determining global optimal solutions to real-scale problems.     

遗传算法实现农村树状供水管网的优化设计

为改善农村树状供水管网的管径设计方案,应用数学建模和最优化理论,提出在确定管网布置方案的基础上,采用整数编码的遗传算法,建立管径组合方案优化模型。以经济性作为目标函数,并结合实例,编制相应计算程序,对某一农村供水管网进行优化设计,与传统设计方案进行对比。结果表明,该优化设计方案在经济性和水力特性都优于传统的设计方案。     

Conjunctive use of Inter-Basin Transferred and Desalinated Water in a Multi-Source Water Supply System Based on Cost-Benefit Analysis

Water shortage has forced coastal cities to seek multi-source water supply with a focus on inter-basin water and desalinated seawater. The differences of water supply costs pose a challenge in the optimal use of multiple water resources. This paper aims to understand the impact of desalinated seawater’s variable costs on multi-source water supply through a cost-benefit analysis method based on a multi-objective optimization model, considering different combination scenarios of desalination yield, streamflow condition, seawater desalting plant (SDP) scheme, water shortage index and utilization ratio of the SDP. The application in the coastal city Tianjin, China shows that the desalination yield has an impact on the tradeoff between the water shortage index and the total water supply cost and an optimal desalination yield can be determined at a turning point. And where the turning point appears is influenced by the utilization ratio of the SDP and streamflow conditions of inter-basin water. Moreover, a single centralized SDP is found to have an overall lower water supply cost than several decentralized small-sized SDPs. Lower water shortage index leads to higher cost, and the unit decrease of shortage index will need more added cost when the shortage index is very low. This method is proven to be effective in identifying the best conjunctive use of inter-basin water and desalinated seawater, which can contribute to relieve urban water shortage.